What is the definition of odd mode in a differential pair?

Conditions

• Applies to the two signal lines of a differential pair.
• The driving voltages on the two lines have opposite polarities.

Reasoning, step by step

1. Observe the two signal lines of the differential pair.
2. Note that one line experiences a positive voltage transition.
3. Note that the other line experiences a negative voltage transition of the same magnitude.
4. Conclude that this opposite-phase driving condition defines the odd mode.

Example

The video shows a waveform plot for odd mode where one line jumps upward while the other jumps downward, maintaining opposite polarity throughout the transition.

Common misconceptions

• Confusing odd mode with differential mode (one is a line property, the other is an applied signal).
• Believing that odd mode means the lines are disconnected.

Watch the explanation

Explore next

• What is the definition of even mode?
• How is differential impedance calculated from odd-mode impedance?
• Why are odd and even modes considered intrinsic properties of the transmission line?